Conventional flash memory technology is described in the following publications inter alia:    [1] Paulo Cappelletti, Clara Golla, Piero Olivo, Enrico Zanoni, “Flash Memories”, Kluwer Academic Publishers, 1999    [2] G. Campardo, R. Micheloni, D. Novosel, “VLSI-Design of Non-Volatile Memories”, Springer Berlin Heidelberg New York, 2005    [3] U.S. Pat. No. 6,301,151 to Engh et al; U.S. Pat. No. 7,151,701 to Combe et al; U.S. Pat. No. 7,292,473 to Niset et al; and U.S. Pat. No. 7,355,896 to Li et al; as well as published PCT document WO 2006138333 and published European patent document EP 1833058.    [4] J. E. Brewer and M. Gill, “Nonvolatile memory technologies with emphasis on flash,” IEEE press series on Microelectronic Systems, John Wiley & Sons, Inc., 2008.The disclosures of all publications and patent documents mentioned in the specification, and of the publications and patent documents cited therein directly or indirectly, are hereby incorporated by reference.